Flexibility of the core bends and allows you to treat a much larger area much more comfortably. Center rod of the stick is surrounded by 8 rotating spindles or rollers, which roll independently over the muscle. 17” long roller is designed to rock back and forth a little bit to find and release painful trigger points. Helps to improve strength, flexibility, and endurance by rapidly preparing muscles for physical activity. Post-activity use enhances and accelerates muscle recovery by dispersing the effects of lactic acid. Standard flexibility, the Travel Stick is the second shortest Stick. It is great for portability; primarily used on legs.